Satellite map shows seismic activity on the island of Sao Jorge after around 1,100 small earthquakes rocked one of Portugal’s mid-Atlantic volcanic islands in the Azores, Portugal, in less than 48 hours. March 21, 2022. CIVISA (Azores Seismovolcanic Surveillance and Information Center)/Handout via REUTERS
- About 1,800 earthquakes have hit the island of Sao Jorge
- Experts fear stronger tremors, volcanic eruption
- Authorities are preparing preventive measures
LISBON, March 22 – A series of multiple small earthquakes that have rocked a mid-Atlantic Portuguese island for three days could trigger stronger shaking or a volcanic eruption, experts said on Tuesday, as authorities urged people not to travel there .
The number of earthquakes recorded on the volcanic island of Sao Jorge in the Azores archipelago since Saturday afternoon has risen to around 1,800 from a previous 1,329, said Rui Marques, head of the region’s seismo-volcanic monitoring center CIVISA.
Only 94 of the 1,800 earthquakes registered so far with a magnitude between 1.7 and 3.3 were felt by the population, Marques told the Lusa news agency.
Sao Jorge, one of nine islands in the Azores, has around 8,400 inhabitants and is part of the central group of the archipelago, which also includes the popular tourist destinations of Faial and Pico, which are also of volcanic origin.
The series of small quakes known as the Swarm, which have so far done no damage, have been reported along the island’s Manadas volcanic fissure, last erupting in 1808.
The communities of Sao Jorge have activated emergency plans as a precaution. Continue reading
“All scenarios are on the table,” Marques told radio station Antena 1. “On the one hand, we could see an earthquake of greater magnitude that can cause some destruction. … On the other hand, we have an outbreak scenario.”
“SEISMIC CRISIS”
Marques urged residents to remain vigilant, although he said the earthquakes were tectonic in origin and related to the movement of the Earth’s tectonic plates rather than volcanoes.
“We should not treat this as a purely tectonic crisis, but rather as a seismic crisis occurring in an active volcanic system,” Marques said.
CIVISA established two additional seismic monitoring stations on the island and dispatched a team to measure bottom gases, an indicator of volcanic activity. Levels have appeared normal so far, Marques said.
The Civil Protection Agency said earlier Tuesday it was working with other agencies to prepare a response in the event of a major earthquake or eruption.
In a separate statement Tuesday night, it advised people to avoid all but essential travel to the lush green island to ensure authorities aren’t faced with “additional restrictions” when they need to help local people.
The sudden surge in seismic activity is reminiscent of the earthquake swarms detected last year before the Cumbre Vieja volcano erupted on the Spanish island of La Palma, some 1,400 km (870 miles) southeast of the Azores. Continue reading
Reporting by Catarina Demony; Edited by Edmund Blair, Jonathan Oatis and Richard Pullin